Plumbite solutions



Patented Apr. 26, 1938 2,115,063 PLUMBITE SOLUTIONS Joseph E. Drapeau, Jr., Hammond, Ind., assignor -to The Glidden Company, Cleveland, Ohio, a

corporation of Ohio No Drawing. Application February 24, 1936'.

Serial No. 65,423

4 Claims.

application is a continuation in part of my co-pending application Serial Number 32,931, filed July 24, 1935. i

This invention relates to plumbite solutions of from the solutions. More particularly, it refers to plumbite solutions in which crystallization of lead oxide is retarded by the use of a very small percentage of metallic antimony, either in its pure state or as an alloy with lead solution, this being a saturated solution at about I In order to reduce the cost of the refining operation, which depends largely on the lead content of the treating solution, it has been suggested that the concentration of lead in the caustic soda 6 solution be increased by using battery scrap,

treated so as to, convert the antimonial lead of the scrap to litharge containing lead antimoniate (Kirk, United States Patent 1, 77,993, October 23, 1934). This treatment does increase the lead solubility to a considerable degree, doubling the I out the necessity for adding large quantities .of

impurities, by adding to the solution asmall quantity of a catalyst comprising metallic anti-. mony in small quantities. I have further investigated this apparently increased, solubility, and have-discovered that the efiect is not an increase in solubility, but the production of stable supersaturated solutions.

When litharge is treated with caustic soda solution at 20 C., a solution of 3.5 grams per 100 g grams of solution can be obtained. If the temsolution, solubilities being expressed as grams litharge per 100 grams of solution,

Table 1-Solubility of litharge at various temperatures Temperature, C. Solubility When litharge is treated with hot caustic solution, easy solubility is thus obtained, but as the temperature drops, crystallization occurs it too much litharge has been added.

If there be added to the litharge various addition agents, there is no change in the solubility at any given temperature. The following table illustrates this point:

Table 2-Solubility of litharge plus addition agents at 20 C.

If, however, the same procedure as used for Table 2 be followed out, except that the litharge be treated at 100 (3., and cooled to 20 0., the caustic soda solutions contain considerably higher percentages of litharge, as indicated in Table 3:

Table 3-'-Solubilit1 of litharge plus addition agents, treating at'100 C. and cooling to 20 C.

Grams n 0 ms marge Addition agent mmlgggn soda l 0.25 dextrose 6. 00

I believe the action of these agents, therefore, to be that of preventing crystallization, by stabilizing the super-saturated solution of lead oxide in caustic soda.

I have now discovered that metallic antimony exhibits this sarne tendency to increase the stability of super-saturated solutions of lead oxide in caustic soda, that the stabilization isobtainable with very small percentages of antimony, and that increasing the antimony percentage above 0.5% definitely decreases the solubility.

The following table indicates the results obtained with metallic antimony. using the same procedure as with Table 3:

.Table 4 Ef7ect of metallic antimony It is apparent that the addition of amounts of metallic antimony above 0.5% deflnitelyreduoe the efiect of the addition.

The addition agent may beadded as metallic antimony, or as an alloy.

I claim:

1. -A plumbite solution of high lead concentration containing a crystallizing retarder comprls ing metallic antimony distributed therein in amounts up to 0.5% based on the litharge content and in amounts sufllcient to stabilize a supersaturated plumbite solution.

2. The method of making a high lead concen- .tration plumbite solution which comprises dissolving litharge in caustic soda in the presence of metallic antimony in amounts suflicient to stabilize a supersaturated plumbite solution.

3. The method of claim 2 in which the amount of antimony is of the order of 0.5% by weight of the litharge present.

4. The method of clahn 2 in which the amount of antimony is 0.00125-0.5% by weight of the litharge present.

JOSEPH E. DRAPEAU, JR. 

